package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.utils.UserHolder;
import lombok.val;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    private final UserServiceImpl userServiceImpl;
    private final StringRedisTemplate stringRedisTemplate;

    @Resource
    private IFollowService followService;

    public BlogServiceImpl(UserServiceImpl userServiceImpl, StringRedisTemplate stringRedisTemplate) {
        this.userServiceImpl = userServiceImpl;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("笔记不存在！");
        }
        Long userId = blog.getUserId();
        User user = userServiceImpl.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    public void isBlogLiked(Blog blog) {
        UserDTO userDTO = UserHolder.getUser();
        if (userDTO == null){
            //用户未登录 无需查询是否点赞
            return;
        }

        Long userId = UserHolder.getUser().getId();
        String key = "blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key,userId.toString());
        blog.setIsLike(score!=null);

    }

    @Override
    public Result likeBlog(Long id) {
        //判断当前登录用户是否点赞
        Long userId = UserHolder.getUser().getId();
        String key = "blog:liked:"+id;
        Double score = stringRedisTemplate.opsForZSet().score(key,userId.toString());

        //如果未点赞 +数据库+1
        if (score == null){
            boolean isSuccess = update().setSql("liked = liked+1").eq("id",id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            //如果已点赞，取消点赞

            //点赞数-1
            boolean isSuccess = update().setSql("liked = liked-1").eq("id",id).update();
            //把用户从set中移除
            if (isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = "blog:liked:"+id;
        //查询top5的点赞用户 zrange key 0 4
        Set<String> top5 =stringRedisTemplate.opsForZSet().range(key,0,4);
        if (top5 ==null || top5.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }

        //2.解析出其中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join("",ids);
        //根据用户id查询用户
        List<UserDTO> userDTOS = userServiceImpl.query()
                .in("id",ids).last("ORDER BY FIELD(id,"+idStr+")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user,UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {

        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败！");
        }
       //查询作者所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id",user.getId()).list();
        //推送笔记id给所有粉丝
        for (Follow follow : follows) {
            //获取粉丝id
            Long userId = follow.getUserId();
            //推送
            String key = "feed"+userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max,Integer offset){
        //获取当前用户
        Long userId = UserHolder.getUser().getId();

        //查询收件箱
        String key = "feed"+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key,0,max,offset,2);

        //非空判断
        if (typedTuples == null || typedTuples.isEmpty()) {
            return Result.ok();
        }

        //解析数据blogId,minTime,offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) {
            //获取id
            ids.add(Long.valueOf(tuple.getValue()));

            long time = tuple.getScore().longValue();
            if (time == minTime) {
                os++;
            }else{
                minTime = time;
                os = 1;
            }
        }

        //根据id查询blog
        String idStr = StrUtil.join("",ids);
        List<Blog> blogs = query().in("id",ids).last("order by field(id,"+idStr+")").list();

        for (Blog blog : blogs) {
            Long userid = blog.getUserId();
            User user = userServiceImpl.getById(userid);
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
            isBlogLiked(blog);

        }

        //封装返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);

        return Result.ok(r);
    }
}
